Generally, the base materials for interlining, notably thermobonding interlining, are divided into two categories: specifically textile base materials and non-wovens. Specifically textile base materials are base materials which are obtained by weaving or knitting yarns, while the non-wovens are obtained by the constitution and consolidation of a layer of fibers or filaments.
Each one of these types of base materials presents advantages and disadvantages and it is up to the user to make a choice as a function of the properties required from the interlining.
Non-wovens are less expensive, but the fibers or filaments therein are irregularly distributed; as a result, not only can differences of density and surface irregulaties occur, but also an inadequate dimensional stability: the non-woven may be irreversibly deformed under the effect of stretching, which, in the case of a thermobonding interlining causes a poor stabilization of the garment piece on which the thermobonding interlining has been heat-bonded. Accordingly, despite their higher price, specifically textile base materials are preferred in those applications where the aforesaid disadvantages of non-wovens are redhibitory, the embodiment by weaving or knitting conferring to them the homogencity, in particular directionwise, which the non-wovens lack.
However, comparatively to non-wovens, specifically textile base materials are less voluminous and less plaisant to the feel.
Attempts have already been made to find a base material for interlining which has both the volume and the feel of a non-woven and the properties of cohesion, springiness and non-stretching of the woven or knitted base material.
This is obtained, in document FR.2 645 180, by juxtaposing a knitted or woven textile base and at least a non-woven layer, and by bonding these two elements by needling using jets of fluid.
The main disadvantage of this composite intended for interlining resides in its production cost which combines the cost of a knitting or of a fabric with that of a non-woven.